Based on previous reports suggesting that higher dose of CD34 cells are associated with better outcomes after nonmyeloablative HCT, high doses of CD34+ cells (>6.5 x 106/kg) should be ideally administered. Nevertheless, to limit donor procedures, only two leukaphereses are required. However, in case the required minimal number of cells (3 x 106 CD34+ cells/kg recipient) cannot be obtained with the first two collections, additional leukaphereses should be carried out unless contra-indicated for the donor.